﻿using System;
using System.Windows.Data;

namespace Infrastructure.TypeConverters
{
    /// <summary>
    /// Converts Int32 to String at data binding
    /// </summary>
    public class NumberToStringConverter : IValueConverter
    {
        #region IValueConverter Members

        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <param name="value">The value produced by the binding source.</param>
        /// <param name="targetType">The type of the binding target property.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if(value == null)
            {
                return Binding.DoNothing;
            }

            return GetString(value);
        }


        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <param name="value">The value that is produced by the binding target.</param>
        /// <param name="targetType">The type to convert to.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if(value != null && !string.IsNullOrEmpty(value.ToString()))
            {
                return GetInt(value);
            }
            else
            {
                return DefaultValue;
            }
        }

        #endregion


        /// <summary>
        /// Gets the string.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns></returns>
        string GetString(object value)
        {
            return value.ToString();
        }

        /// <summary>
        /// Gets the Int32.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns></returns>
        int GetInt(object value)
        {
            int retval;
            int.TryParse(value.ToString(), out retval);
            return retval;
        }

        /// <summary>
        /// Gets or sets the default value.
        /// This value will be the default return value, e.g. the initial value in the control.
        /// </summary>
        /// <value>The default value.</value>
        public int? DefaultValue { get; set; }
    }
}